Recherche avancée

Sur d’autres sites (13416)

• ffmpeg hevc decoding fail [android]

  8 mars 2016, par revannen

  I am trying to decode h.265 with x265 and ffmpeg library, so that I downloaded ffmpeg 2.8.6 tar and x265 1.9 ver from the official site.

  now, the problem is when I decode h.264 with
  avcodec_find_decoder(AV_CODEC_ID_H264) ;
  is totally fine. :)

  but, when I try to decode h.265 with
  avcodec_find_decoder(AV_CODEC_ID_H265) ;
  it tells lots of error log.
  like.

  I/ffmpeg(4153) : nal_unit_type : 32, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : nal_unit_type : 33, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : nal_unit_type : 34, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : nal_unit_type : 19, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : No start code is found.

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : PPS id out of range : 0

  I/ffmpeg(4153) : Error parsing NAL unit #0.

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : PPS id out of range : 0

  I/ffmpeg(4153) : Error parsing NAL unit #0.

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : PPS id out of range : 0

  I/ffmpeg(4153) : Error parsing NAL unit #0.

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : nal_unit_type : 1, nuh_layer_id : 0temporal_id : 0

  I/ffmpeg(4153) : PPS id out of range : 0

  I/ffmpeg(4153) : Error parsing NAL unit #0.

  E/decode(4153) : [407] [idvr] Error while decoding frame ! [%d]

  E/native(4153) : FAIL......-12

  1. Is it ffmpeg error ? or x265 library error ?

  2. should I modify some configuration key value in build level ? or ffmpeg running time level ?

  3. I would like to know why ffmpeg library keep saying like "No start code is found" && "PPS id out of range" [it is occur in only 265 decoding case, not 264.]

• ffmpeg quality conversion options (video compression)

  25 septembre 2020, par Jason Hunter

  Can you provide a link, or an explanation, to the -q:v 1 argument that deals with video/image quality, and compression, in ffmpeg.

  


  Let me explain...

  


  for f in *
   do 
     extension="${f##*.}"
     filename="${f%.*}"
     ffmpeg -i "$f" -q:v 1 "$filename"_lq."$extension"
     rm -f "$f"
   done


  


  The ffmpeg for loop above compresses all images and videos in your working directory, it basically lowers the quality which results in smaller file sizes (the desired outcome).

  


  I'm most interested in the -q:v 1 argument of this for loop. The 1 in the -q:v 1 argument is what controls the amount of compression. But I can't find any documentation describing how to change this value of 1, and describing what it does. Is it a percentage ? Multiplier ? How do I adjust this knob ? Can/should I use negative values ? Integers only ? Min/max values ? etc.

  


  I started with the official documentation but the best I could find was a section on video quality, and the -q flag description is sparse.

  


  


  -frames[:stream_specifier] framecount (output,per-stream)
  
Stop writing to the stream after framecount frames.
  
.
  
-q[:stream_specifier] q (output,per-stream)
  

  
-qscale[:stream_specifier] q (output,per-stream)
  
Use fixed quality scale (VBR). The meaning of q/qscale is codec-dependent. If qscale is used without a stream_specifier then it applies only to the video stream, this is to maintain compatibility with previous behavior and as specifying the same codec specific value to 2 different codecs that is audio and video generally is not what is intended when no stream_specifier is used.

  


  


• Piwik 2 reaches end of life soon (December 2017), update now !

  7 décembre 2017, par Piwik Core Team — Community

  In less than three weeks, Piwik 2 will be no longer supported. This means that no further (security) updates will be released for this version. As per our Long Term Support announcement, Piwik 2.X is supported for 12 months after the initial release of Piwik 3.0.0 which was on December 18th 2016. Therefore, Piwik 2 will no longer receive any updates after December 18th 2017.

  It has been almost a year since we released Piwik 3 and we highly recommend updating to Piwik 3 ASAP. The major new release came with a new UI, performance and security improvements. If you are still on Piwik 2, the security improvements alone should be worth updating your Piwik to Piwik 3 now. We cannot recommend this enough.

  The update to Piwik 3 should be smooth, but may take a while depending on the amount of data you have.

  • If you have any problem with the update, feel free to get in touch with us, or ask in the forums.
  • If you are currently using Piwik self-hosted and would like to be upgraded, plus your Piwik managed in the official Cloud-hosted service, contact InnoCraft Cloud and they will migrate your database.

  At Piwik and InnoCraft, the company of the makers of Piwik, we have seen many thousands of Piwik installations upgraded over the past year and look forward to an exciting future for Piwik 3 and beyond !